The invention relates to a system with virtual volume access and management.
Spiraling increases in processing capability have made computers indispensable in the modern world. Concurrently, information storage systems have become an important part of these computers to handle the resulting data explosion. Further, the need for a pervasive access to mission-critical data scattered among heterogeneous platforms has increased the complexity and cost of managing storage in corporate environments.
The storage and management of data have driven the development of new storage architectures Network Attached Storage (NAS) and Storage Area Network (SAN) to meet growing storage demand.
In a NAS, intelligent storage devices connect directly to the network and are dedicated to one function: file serving. A NAS device lets administrators attach intelligent devices to networks, which are capable of directly retrieving and transmitting information to users. In general, a NAS product functions as a server in a client/server relationship. The NAS device has its own processor, a dedicated operating system or micro kernel, and processes file I/O protocols, such as NFS, to manage the transfer of data between itself and its clients. To applications running on the network, the NAS device appears to be a server. To a client, the NAS device is a large hard disk.
In a SAN environment, the function of storage is detached from network servers and centralized and managed as a separate network resource. SANs that are based on Fibre Channel buses have recently emerged as one high performance data communications environment available today to interconnect servers and storage. Running at Gigabit speeds and built on open standards, SANs offer better scalability, fault recovery and general manageability than conventional client-server LAN based approaches.
Although SANs may be connected together in a network, SANs are typically not network aware. As such, requesters such as servers can directly access drives attached to the SAN system. However, for accesses to remote drives attached to remote SANs, the requesters have to specifically direct their requests to the remote SANs using specialized drivers or code. As such, the software has to be customized to access remote data storage devices.
With the increasing demand for storage and continually lower prices of storage, system administrators are frequently facing the challenge of seamless expansion of online storage capacity. This requirement changes the dynamics of the way the data is stored on the disk or the tape and the way the reads and writes are done on the storage devices. Thus, users are demanding better ways of maintaining the data storage system and increasing storage performance and/or capacity to meet new demands.